Transcriptome analysis of Polianthes tuberosa during floral scent formation

Polianthes tuberosa is a popular ornamental plant. Its floral scent volatiles mainly consist of terpenes and benzenoids that emit a charming fragrance. However, our understanding of the molecular mechanism responsible for the floral scent of P. tuberosa is limited. Using transcriptome sequencing and de novo assembly, a total of 228,706,703 high-quality reads were obtained, which resulted in the identification of 96,906 unigenes (SRA Accession Number SRP126470, TSA Acc. No. GGEA00000000). Approximately 41.85% of the unigenes were functionally annotated using public databases. A total of 4,694 differentially expressed genes (DEGs)were discovered during flowering. Gas chromatography-mass spectrometry analysis revealed that the majority of the volatiles comprised benzenoids and small amounts of terpenes. Homology analysis identified 13 and 17 candidate genes associated with terpene and benzenoid biosynthesis, respectively. Among these, PtTPS1, PtDAHPSs, PtPAL1, and PtBCMT2 might play important roles in regulating the formation of floral volatiles. The data generated by transcriptome sequencing provide a critical resource for exploring concrete characteristics as well as for supporting functional genomics studies. The results of the present study also lay the foundation for the elucidation of the molecular mechanism underlying the regulation of floral scents in monocots.